Install was uneventful. The clearance is really tight near the driver's side differential mounting bolt head, but otherwise intall was easy on 8" ramps.

I went with the rear bar only because I felt the rear was quite a bit looser than the front. I also thought if the setup felt odd, I could get the front bar later for $170. The RSB adjusts for 85%, 130%, and 190%. I just wanted a little less roll out back so I set it to the first setting. After a 30 minute drive, so far, so good. Roll has be reduced quite a bit out back without any nasty snap oversteer and suspension "rocking" when making tight, off-camber, slower speed turns. If you set a sway bar too stiff out back, you don't the suspension work as independently as it should and the rear of the car will rock side to side a bit because the bar is working against the suspension.

 

I did the same thing as a test.

I ended up reinstalling a adjustable aftermarket front bar and from my experinece I do not recommend rear bar only tuning. I just don't see this platform as having the same things in play as FF cars.

[edit]
And I really do not believe Hothkcis, who makes Cobb suspension parts when the spit out stiffness vs oem numbers on their sway bars, at least not on this platform.

 

so the cobb parts are all made by Hotchkis? Im assuming to COBB specs though?

I'm eyeing them up for a complete spring and sway package, they're spring rates and lowering heights seem different than Hotchkis.

 

I've never heard that Hotchkis makes the parts for Cobb either. I guess it's entirely possible though because the equipment needed to bend the bars isn't cheap and the tolerances have to be pretty tight. What's odd though is Cobb claims different stiffness settings than Hotchkis.

Right now, the car feels really good with the car at the lowest setting (85% stiffer). The car still rolls out back, but only about 40-50% as much as it did. It's what I was looking for. I don't foresee myself adjusting to a stiffer setting because I don't want to compromise the independent movement of the suspension or make the car an oversteering nightmare. I'm still trying to find the oversteer limit. It's actually quite higher than I thought it would be with the stiffer bar. Maybe my opinion will change as time goes on.

 

Hotchkis makes the Cobb sway's and springs. Cobb's claim that the springs are 15% stiffer then oem are questionable. They had no clue that the Z has two different oem suspension's with very different rear spring rates. I'll be suprised if they are plus 15% to the revised Z suspension's 314./427 rates.

Course as allway's if anyone will send me a single front and single rear spring I will verify the spring rates and send them back my dime within 48 hours of receipt.

I do not belive the vs oem number on the bar's are accurate. We shouldn't be tuning by numbers anyhow, we should be adjusting to the settings that work, number's be damned.

 

Do you know what the spring rates are for the 07+G35 Sedan with the Sport package? I am wondering if the cobb springs might be another option to the other 07+ aftermarket. The cobb site only says it is for the z and g coupe.

 

I would imagine stiffness setting on most of the suspension parts such as sway bars are compared to the 350z. I don't think any manufacturer would rate the percentage comparing it to the sedan because that is the last type of costumers they have in mind when selling these products.

 

Totally agree.

Last night I worked late and left around 1130 which meant I could really throw the car around. I am very happy with the setup. I still have plenty of roll and suspension movement to keep the tires well planted and the back end doesn't swing out unexpectedly nor early like I was fearing. The limits are definitely higher. The front doesn't feel loose or twitchy either. It's exactly what I was looking for mostly street driving. I might have a different opinion if I auto-x'd on a regular basis and was really tossing the car around hard at slower speeds.